I. Solution Photochemistry of Camphor
Irradiation of camphor in solutions of 95% ethanol or n-heptane produces mainly α-campholenic aldehyde. In ethanol a bicyclic acetal is also formed, while in n-heptane a bicyclic enol ether is formed instead of the acetal. Deuterium labelling experiments indicate that the acetal is formed by reaction of a bicyclic oxycarbene with ethanol, and that the enol ether is formed from this oxycarbene in part by reaction with n-heptane and in part by an intramolecular rearrangement. Two cyclobutanols and an oxetane which are also produced on irradiation of camphor arise by secondary photolysis of α-campholenic aldehyde. 1,2,2-Trimethylcyclopent-3-enyl methyl ketone, previously thought to be a major product of the solution photolysis of camphor, has been synthesized and shown to be absent from our product mixtures.
II. Synthesis and Solution Photochemistry of 222-Dimethylcyclobutanone
2,2-Dimethylcyclobutanone has been synthesized by a new and convenient route which gives the desired product in 49% overall yield from commercially available materials. Irradiation of 2,2-dimethylcyclobutanone in methylene chloride or in pentane produced little or no 2,3-dihydro-2,2-dimethylfuran. This observation is contrasted with the results of our study of camphor photochemistry.
I. Solution Photochemistry of Camphor
Irradiation of camphor in solutions of 95% ethanol or n-heptane produces mainly α-campholenic aldehyde. In ethanol a bicyclic acetal is also formed, while in n-heptane a bicyclic enol ether is formed instead of the acetal. Deuterium labelling experiments indicate that the acetal is formed by reaction of a bicyclic oxycarbene with ethanol, and that the enol ether is formed from this oxycarbene in part by reaction with n-heptane and in part by an intramolecular rearrangement. Two cyclobutanols and an oxetane which are also produced on irradiation of camphor arise by secondary photolysis of α-campholenic aldehyde. 1,2,2-Trimethylcyclopent-3-enyl methyl ketone, previously thought to be a major product of the solution photolysis of camphor, has been synthesized and shown to be absent from our product mixtures.
II. Synthesis and Solution Photochemistry of 222-Dimethylcyclobutanone
2,2-Dimethylcyclobutanone has been synthesized by a new and convenient route which gives the desired product in 49% overall yield from commercially available materials. Irradiation of 2,2-dimethylcyclobutanone in methylene chloride or in pentane produced little or no 2,3-dihydro-2,2-dimethylfuran. This observation is contrasted with the results of our study of camphor photochemistry.
I. Solution Photochemistry of Camphor
Irradiation of camphor in solutions of 95% ethanol or n-heptane produces mainly α-campholenic aldehyde. In ethanol a bicyclic acetal is also formed, while in n-heptane a bicyclic enol ether is formed instead of the acetal. Deuterium labelling experiments indicate that the acetal is formed by reaction of a bicyclic oxycarbene with ethanol, and that the enol ether is formed from this oxycarbene in part by reaction with n-heptane and in part by an intramolecular rearrangement. Two cyclobutanols and an oxetane which are also produced on irradiation of camphor arise by secondary photolysis of α-campholenic aldehyde. 1,2,2-Trimethylcyclopent-3-enyl methyl ketone, previously thought to be a major product of the solution photolysis of camphor, has been synthesized and shown to be absent from our product mixtures.
II. Synthesis and Solution Photochemistry of 222-Dimethylcyclobutanone
2,2-Dimethylcyclobutanone has been synthesized by a new and convenient route which gives the desired product in 49% overall yield from commercially available materials. Irradiation of 2,2-dimethylcyclobutanone in methylene chloride or in pentane produced little or no 2,3-dihydro-2,2-dimethylfuran. This observation is contrasted with the results of our study of camphor photochemistry.